The Importance of Sulfur Human Nutrition

SULFUR – THE FORGOTTEN NUTRIENT

Sulfur is an inorganic element and forms part of several molecules in the body, including amino acids, proteins, enzymes, vitamins, and more.1 Following calcium and phosphorus, sulfur is the third most abundant mineral in the human body, representing ~0.3% of total body mass.2 Dietary sulfur comes from protein where 2 of the 20 amino acids, methionine, and cysteine, contain sulfur (the sulfur-containing amino acids; SAAs). The amount of SAAs in protein varies according to the source, e.g., dairy is 4% SAAs and egg whites 8% SAAs.3 Additionally, glutathione (a natural intracellular antioxidant) provides a source of dietary sulfur and is found in fruits and vegetables.4 Currently, there is no recommended dietary allowance (RDA) for sulfur. There is, however, a recommended daily intake for the sulfur-containing amino acids. The estimated requirement for methionine (combined with cysteine) was determined in 1989 to be 14 mg/day per kg body weight in adults.3

DO WE GET ENOUGH SULFUR IN THE DIET?

It is vital that there is a good supply of sulfur in the diet to maintain synthesis of the SAAs. Methionine, cannot be synthesized in the body and therefore directly relies on an adequate intake of protein. While cysteine is synthesized in the body; the process requires a steady supply of sulfur.8 It’s assumed that sulfur intake in the diet is adequate. However, this is based on SAAs, not sulfur directly.2 Further, the requirements for SAAs are based on nitrogen balance and likely under-estimate the dietary need for sulfur.3 As such, there is increasing evidence that our needs for methionine, specifically, are not being met through diet.3 This is further complicated by the admission that intakes don’t have to be deficient to cause physiological disruption. Even marginally sufficient intake may not be enough. Furthermore, continued evidence to show that dietary intakes have declined due to modern agricultural processes.2,9 The perception that supply is adequate is, therefore, problematic.

THE ROLE OF SULFUR IN THE BODY?

Historically, sulfur has been considered important in soil and plant health, rather than human health. However, its role – direct and indirect – is significant. Best known is the role of sulfur and its benefits for skin, including appearance (skin structure), acne, wound healing, and overall skin health.5 Sulfur provides structure and elasticity at a molecular level. Disulfide bonds link skin proteins, like collagen and elastin, and are critical for skin’s strong, yet flexible characteristic.1 These bonds can be stretched, yet retain shape once released. Additionally, as an integral part of the antioxidant and detoxification processes, sulfur is necessary to protect and maintain proper skin growth.6 Similarly, sulfur supports connective tissue. Tendons and ligaments rely on sulfur for proper cross-linking (disulfide bonds) in addition to extracellular matrix proteins like glycosaminoglycan’s (GAGs) and hyaluronic acids (HA), which are highly sulfonated, and provide strength and cushion.3,7 In the liver, sulfur plays two critical roles. As a significant component of glutathione, the most prevalent antioxidant in the body, sulfur helps the body react to oxidative stress and maintain homeostasis, which is particularly relevant to exercise and aging. And as part of phase 2 detoxification, sulfur is essential to the metabolism and excretion of harmful substances.6,8 There are many other roles, such as free radical scavenging, and regulation of gene expression.6 Further, sulfur indirectly influences all processes of compounds or metabolites in which it is a key component. This includes n-3 and n-6 polyunsaturated fatty acids, and minerals such as Selenium, Zinc, Copper, and Magnesium.3 Bottom line, the role of sulfur in the body is broad, impactful, and should not be underestimated.

OPTIMSM® AS A SOURCE OF SULFUR

MSM, or methylsulfonylmethane, a popular food supplement, is composed of sulfur, oxygen, and methyl groups.2 It is naturally found in a variety of foods, such as milk, fruits, tomatoes, corn, coffee, and tea.10 However, supplemental intake may prove necessary, given the confusion as to how much sulfur is required in the diet. Several studies have demonstrated that sulfur from MSM can be incorporated into SAAs, proteins, and various tissues.11,12 When consumed in doses ranging between 1.0 g/day and 6.0 g/day over several weeks to months, no significant adverse events have been reported.13-15 Furthermore, MSM has been shown to benefit joint health (joint pain, swelling, and improved mobility),16-20 improve skin quality (elasticity, firmness, and reduced wrinkles),21 suppress seasonal allergic rhinitis,22,23 and reduce exercise-induced oxidative stress and muscle damage in humans.24,25 This is likely a result of MSM acting as a sulfur donor in addition to stimulating glutathione and other relevant molecules to reduce the impact of inflammation and oxidative stress. OptiMSM®, the only branded and U.S.-manufactured form of MSM, is produced by Bergstrom Nutrition and is utilized in the majority of research on MSM and its benefits. Because it is the only distilled MSM in the world, the purity, consistency, and safety of OptiMSM are unmatched, and the best option for research. A recent study proved rapid absorption of OptiMSM and incorporation into tissue proteins.12 OptiMSM provides the body an easily accessible pool of sulfur which spares the essential sulfur-containing amino acids (SAAs) methionine and cysteine from being metabolized for their sulfur. It’s role as a sulfur donor, and its ability to preserve SAAs explains the broad range of health benefits observed with OptiMSM supplementation. Bergstrom Nutrition, who sponsored the study, continues to invest in research to support the efficacy, safety, and applications of OptiMSM. While there is a significant amount of research to support the role of MSM in human health,13 admittedly, less has been reported on the specific role of the sulfur per se. However, given the extent to which MSM is shown to influence various aspects of human health, there is a growing appreciation of its “protective” role in the diet. This is particularly relevant to active nutrition and active-aging where consumers are looking for solutions to help them remain “ageless.”